Among the marksmanship arts is that known as "match" or "bench rest" shooting, participated in by highly skilled and practiced individuals employing finely tuned firearms and so-called "match" ammunition. The object of such marksmanship is basically the placement of all bullets through the same hole on the target at whatever range is being fired. In the accomplishment of such a marksmanship feat, the mechanical variables in ammunition performance must be reduced to a minimum, and in the subject of this disclosure it is specifically the cartridge case flash hole considerations attributable to reducing ballistic variables in ammunition performance to a minimum with which we are dealing.
The present invention relates to an improved cartridge case flash hole uniforming tool of a type employed by those engaged in reloading the cases of spent cartridges primarily for use in high accuracy applications such as those previously described as match or bench rest shooting, and in particular to a tool specifically adapted to consistently provide a reamed flash hole profile and chamfered opening therefrom into the cartridge case powder chamber that will, from cartridge to cartridge, communicate a uniform full-blown primer flash bloom from the primer pocket to the powder chamber for consistent ignition and detonation of the propellant charge so that cartridge factor accuracy attributable to propellant burning profiles and pressure generation in providing bullet driving force is highly consistent and uniformily repeatable from round to round.
Flash hole reaming and chamfering operations have been previously accomplished by reloaders primarily as a manual operation employing a uniforming tool such as that one shown and taught in U.S. Pat. No. 4,807,511 dated Feb. 28, 1989, by Markle, the applicant herein, which tool represented a substantial improvement over the state of the art then existent, and to this date remains fully adequate for flash hole uniforming in general reloading operations to provide cartridges intended to be used in typical target shooting and hunting activities. However, where the nature of shooting accuracy fully demands a reduction to an absolute minimum of all variables, including those attributable to cartridge accuracy factors with respect to reliably repeatable ammunition performance characteristics from round to round, flash hole reaming and chamfering preparation with the improved uniformer of instant invention does provide a distinct improvement over currently available tools for this purpose as more fully set forth in the detailed description of the invention that follows.